Research on hydrogen control strategy in advanced pressurized water reactor nuclear power plant

The design of new-built nuclear power plant (NPP) must achieve the result that the possibility of early radioactive release or large radioactive release is 'practically eliminated', and the containment failure caused by hydrogen detonation is one of the severe accident conditions that shall be 'practical eliminated'. So each kind of hydrogen elimination measures should be analyzed and investigated to establish assessment method. And it could provide supporting method for reviewing on design selection of hydrogen control strategy for advanced pressurized water reactor (PWR) NPP. Considering the hydrogen control strategy in severe accident management, it is the key issue to conduct review on combustibility of local space in containment. Based on the criterion of combustibility, flame acceleration (FA) and deflagration to detonation transition (DDT), 3D-CFD code was used to simulate the combustibility and hydrogen risk in steam generator compartment under representative severe accident condition. The results indicate that the combustibility still exists in large zone of compartment, even though the discharging gas is entrained with a high percentage of steam, and igniters with design of reasonable layout are able to ignite and eliminate hydrogen. The analysis method in this paper can be used to assess the design selection of hydrogen control strategy in NPP. (authors)